1. Field of the Invention
This invention relates to a printer with a scanner function, which takes in images with its scanner function and prints out the images with its printer function, and its control method and control program product.
2. Description of the Prior Art
Printers with a scanner function currently on the market are not equipped with an image-processing engine for their simple structure. They take in image data (RGB signals) with their scanner functions, convert the image data as they are into data for printing (CMYK signals) based on a prescribed look-up table, and prints out the images with their printing functions.
On the other hand, there are available methods of taking text in with a scanner function and increasing clearness, or distinctness, of letters in printing them. According to one of those methods, letters are printed in distinct black, while the background of the letters is regarded as white. In this regard, a useful technique is known. According to the technique, while the RGB signals of image data taken in with a scanner function are converted into CMYK signals for printing, RGB signals within the vicinities of the values representing darkest red, green, and blue are converted into black (K)-100% signals and RGB signals within the vicinities of the values representing lightest red, green, and blue are converted into CMYK-0% signals (see, for example, Japanese Unexamined Patent Publication No. 2002-252781).
When text is taken in with a conventional printer with a scanner function and without the above clearness-improving function, the reflection of the light of its light source may cause a tinge around each letter. If it happens, the printer with a scanner function converts the image data as they are into data for printing and hence the tinge around each letter is printed as minute dots if the printer with a scanner function is capable of minute dots. Thus, the outlines of printed letters are blurred and the printed letters are rendered unclear. With a conventional printer with a scanner function and the above clearness-improving function, this problem can be avoided. However, the printer is capable of printing only in black and white, but incapable of printing in gradation.